Arcane items of medical obscurity are the neurologist's lifeblood. We can figure stuff out. This blogger is interested in diseases that affect people-- go somewhere else for results of rat research. Information is meant to be advanced but clinically relevant esoterica.

Friday, April 12, 2013

Papilledema and obstructive sleep apnea syndrome.

Abstract

OBJECTIVES:

To characterize the pathogenesis and clinical features of optic disc edema associated with obstructive sleep apnea syndrome (SAS).

METHODS:

A series of 4 patients with SAS and papilledema (PE) underwent complete neuro-ophthalmologic evaluation and lumbar puncture. In 1 patient, continuous 24-hour intracranial pressure (ICP) monitoring was also performed.

RESULTS:

All 4 patients had bilateral PE that was asymmetric in 2. Three patients had optic nerve dysfunction, asymmetric in 1, unilateral in 2. Daytime cerebrospinal fluid pressure measurements were within normal range. Nocturnal monitoring performed in one patient, however, demonstrated repeated episodes of marked ICP elevation associated with apnea and arterial oxygen desaturation.

CONCLUSIONS:

We propose that PE in SAS is due to episodic nocturnal hypoxemia and hypercarbia resulting in increased ICP secondary to cerebral vasodilation. In these individuals, intermittent ICP elevation is sufficient to cause persistent disc edema. These patients may be at increased risk for developing visual loss secondary to PE compared with patients with obesity-related pseudotumor cerebri because of associated hypoxemia. The diagnosis of SAS PE may not be appreciated because daytime cerebrospinal fluid pressure measurements are normal and because patients tend to present with visual loss rather than with symptoms of increased ICP.